Groundwater Arsenic Occurrences in Bangladesh and Mitigation Options Goldschmidt2015 Prague, CZ, 16-21 August 2015 Groundwater Arsenic Occurrences in Bangladesh and Mitigation Options Kazi Matin Ahmed, PhD Department of Geology University of Dhaka Dhaka, Bangladesh kmahmed@du.ac.bd

Groundwater as the Sources for Drinking & Irrigation Water

Map of Arsenic Occurrence 1998-99 Survey 2002-03 Survey Add year with large fonts 3

Over 5 million wells tested! Most severely affected areas are in the southern part of the deltaic plains Some contamination in the north east, northwest is least contaminated Hills in the southeast safe Distribution is controlled by surface geology Deeper wells are mostly safe Change color for the 20-40% class to yellow 4

Geology and Arsenic Distribution

Basin Model

Impact of Arsenic on Rural Water Supply Source: WaterAid Bangladesh

Possible Impacts on Rice Production 50% reduction Delete one map, add the graph on yield reduction of rice ‘Parrot beak’ Duxbury et al 8

Number of People with Skin Lesions Surveys identified around 30,000 having arsenical skin lesions Overall prevalence is about 1 in 1000, however, local studies reported much higher numbers; Argoss et al - double mortality rate due to CVD for exposure in access 150 ppb; Wasserman et al reported reduced intellectual development of kids. Alan Smith predicts 1 in 100 dying of cancer at 50 ppb, and 1 in 10 at 500 ppb Delete one map, add a picture of skin lesions 9

Arsenic Removal Technologies Sono 45-25 A –Household ARTs: Alcan, Nelima, Read F, Shawdesh, Sono B - Community ARTs: Sidko Sidko MAGC/ALCAN READ-F

Well Switching

Alternative Safe Water Options

Deep Tube Wells (GOB, 2002)

Rural Piped Water Systems (GOB, 2002)

Subsurface Arsenic Removal

Number of People Exposed to >50 ppb Change title GOB, 2002 16

GOB/UNICEF 2009 MICS The results of the Multiple Indicator Cluster Survey (MICS) in 2009 estimated that approximately 22 million people were exposed to arsenic concentrations above 50 μg/L, and approximately 36 million above 10 μg/L. The results of the Multiple Indicator Cluster Survey (MICS) in 2013 estimated that approximately 19.6 million people were exposed to arsenic concentrations above the Bangladesh Drinking Water Quality Standard of 50 μg/L http://www.unicef.org/bangladesh/knowledgecentre_6868.htm

Arsenic in BRAC WASH Area Source: Nepal C Dey, Fazlul Karim and Sifat-E-Rabbi, 2013. Use of tubewell water for different purposes at household level: safety practices in rural Bangladesh, in Achievements of BRAC Water, Sanitation and Hygiene Programme Towards Millennium Development Goals and Beyond, Research Monograph Series No. 60, p11-31, Research and Evaluation Division (RED), BRAC.

Large Number of Untested Wells 50% of households (53/105) knowingly drink from unsafe well

Possible Safe Water Options for Different Regions Out of 19.0 million, 10.9 million people can be covered by Deep TW with No 6 or TARA hand pump The rest 8.1 million people are to be covered by PSF, DW, AIRP etc If well can be installed up to deep aquifer having gravel problem, nearly 5.7 million out of 8.1 million can be served with Tubewell 20

Concluding Remarks Natural arsenic occurrence in the alluvial aquifer is and will remain as a major challenge for water supply in Bangladesh ; A major public health concerns; thousands of patients with visible symptoms; likely impacts on food security; A large number of mitigations options are available, DTW has been the most effective one; Still millions are exposed to arsenic above current BD limit (50 ppb), number almost doubles if WHO provisional guide line value (10 ppb) is considered; Targeted efforts are necessary to provide safe water to all who are still drinking water having As above safe limits; Impacts of As on Irrigation and food security need special attention.

Thank you all!